The present invention relates to a current output circuit and to, for example, a current output circuit disposed in a position detection apparatus.
A position detection apparatus that detects a contact position of an electromagnetic induction pen which will be in contact with a panel surface is mounted on an electromagnetic induction panel. The position detection apparatus includes a sensor coil disposed on the panel and a current output circuit that outputs a high frequency current to the sensor coil. The position detection apparatus detects a contact position of a contact object on the panel based on a voltage signal that is received by the sensor coil.
Japanese Unexamined Patent Application Publication No. 2003-202955 discloses a current transmission circuit (current output circuit) that is disposed in a position detection apparatus. This current transmission circuit uses a separation circuit to separate an analog sine wave into two half-wave signals, converts the voltages of the half-wave signals into currents, combines the currents, and outputs the combined current. Japanese Unexamined Patent Application Publication No. 2011-97191 discloses a specific configuration of the separation circuit.